This Hubsan 4-Channel 2.4HSz Transmitter is compatible with the X4 H107C, and one of our favorites, the Estes Proto X. This controller is nice to replace the original mini controller that the Estes Proto X and Hubsan H111 Q4 come with. For people who can’t stand this mini controller and don’t have the tiny hands to use it, the Hubsan 4-Channel Transmitter is going to be your best option in transmitters. It supports both Mode 1 and Mode 2 stick configurations. Mode 2 is most common in the US but international users may be accustomed to flying in Mode 1. This transmitter has an LCD info screen that displays the remaining battery, stick trim settings, and other data. The red/green LED light indicates the proper binding with the receiver. It also has an “Expert Mode” which makes the receiver a lot more sensitive in the way it moves. With it being in Expert Mode, it’s possible to achieve flips and rolls with the receiving quadcopter.